Telephone system



Dec. 13, 1927. 1,652,187

a TANKE TELEPHONE SYSTBI r11: Sept. 1. 1921 2 Sheets-Sheet 1 Dec. 13, 1927.

E. TANKE wawraous sxs-rsu Filed Sept. 1. 1921 2 Sheets-Sheet 2 Patented Dec. 13, 1927.

UNITED STATES PATENT OFFICE.

TAKE. FALKENHAGEN, NEAR SERGEFELD K38. OSTHAVELLAND, GERKANY, ASSIGNOB, BY KESNE ASSIGNMENTS, TO AUTOMATIC ELECTRIC DIG, OF CHICAGO, ILLDIOIB, A CORPORATION OF DELAWARE.

TELEPHONE SYSTEM.

Application fled September 1, 1021, Serial No. 487,572, and in Germany September 25, 1818.

The present invention is a modification of the circuit arrangements for telephone installations described in the German Patent Number 275,655. In that patent the subscribers lines are grou (1 according to the fre uency of their ca and provision is ma e at the first number impulse receiver for determining whether the calling line shall be connected or not to an operators position, that is whether the call is to be set up on the semi-automatic or full automatic systems. According to the above atent, these circuit changes are made depen cut on certain switching devices at the callin stations or at the exchange, which are ently arran ed according to the system to which the su cribers belong. These switching devices directly actuate the members which connect up the operating positions. In installations in which repeaters are inserted between the calling lines and the first number im ulse receivers, this direct action could only be effected over special leads provided for the purpose. In the modification according to the present invention, these special leads are not required and the devices for connecting up an operators position are controlled not directly by the characteristic differences imposed on the calling subscribers line, or on a group of such lines, but indirectly from the repeater. This arrangement enables the repeaters, as well as the first number impulse receivers, to be used in common for setting up a call either on the full automatic or semi-automatic systems.

According as certain circuit changes are, or are not, effected at the repeater, the devices for connecting u an operators position will, or will not, actuated. The re-' geaters may be at the same exchange as the rst number receivers, or at a different exchange. Also the preselecting devices may be at the same exchange as the repeaters, or the may be placed in different exchanges. he circuit changes at the repeater can be effected %means of a relay at the repeater itself. e distinguishing characteristics which control the action of the relay, may be imposed either at the subscribers station or at the exchange. In the latter case, this characteristic may be supplied by special contact arms or battery or other potentials imposedat the pr devices. If the connection is set up over more than one preselecting device, and the subscribers hnes are rouped at the exchange according as they elong to the full or semi-automatic systems, the distinguishing characteristics are referably imposed at the selectors of the ast preselecting step. They may, however, be imposed at the selectors of thefirst preselecting step, if the succeeding preselecting devices are to be used in common for set ting up a call on either system. The relay at the re ter is then operated over the selectors o the second or other succeeding preselecting device.

Besides the circuit changw, which connect up, or prevent the connection of, an operators position, other changes are effected according to the invention, which render the operation more eflicient. For instance, circuits which are necessary for the full auto matic, but are not required for the semiautomatic working, are cut off because they may cause unnecessary noises in the receiver of the operator.

Fi 1 and 2 of the accompanying drawing s ow by way of example circuit connections according to the invention, applied to an installation with two preselectmg devices, VW and W If the frequently calling subscriber V, whose station is equipped for full automatic working, calls up, the two preselectors W1 and VW are set in known manner.

B the setting of the second preselector V W relays A and B at the repeater U. are energized. Relay A by closing its front con tact 100, closes the circuit of relay V, from earth, battery V,, 100, 101, earth. Relay C is also energized when the arms of the preselector VW reach the repeater, but it is slow acting, so that contact 129 in the circuit of a relay S is already opened, when the contact 103 of rela C is closed, so that relay S is not ener zed. The lead 0 of the group selector G r (Fig. 2) is earthed at contact 104 of relay V so that relay C is energized from earth, battery, ofi normal contact k C lead 0, 104, earth. Relay C at 105 connects a relay C, at GW; to the 0 lead, so that C is also energized and locks itself over a contact 106 in a circuit independent of C from earth, battery 0,, 106, 05 normal contact 107, e, 104, earth. At

contact 108, windin II of relay B, is connected to the 0 lead by relay C, and relay B, is ener ized.

W'in in III of relay B is connected to the b lea over 109 and 111, and relay A, to the a lead at 110. Winding III of relay B is connected over the front contact 111 of relay B,, so that this winding can only be energized over the I) lead after its winding II has been connected to the 0 lead. Although contact 112 has been closed by relay B, and contact 113 by rela C, relay DC cannot be energized over t e g lead, since the necessary potential has not been g pvglied to the d arm of the preselector The further setting up of the call is immaterial for the invention; the action is briefly, as follows :The first series of impulses sent out by the subscriber V 15 transmitted'by relay A at the repeater U. and relay A, at the group selector GW and energizes the lifting magnet H over contacts 115 of relay A1 and 116 of relay B.. When relay V at the repeater is energized at the first impulse from 'earth, battery, V,, 117, 100', 101, earth it causes battery to be applied at 118 to the 6 lead and thereby a circuit to be closed for relay B over its winding III from earth battery, resistance 10, 119, 118 144. ,139, III, 109, winding III of 13,, emit. The excitation of relay B is thus independent of relay G which at the first lifting step of the group selector GW is de-energized in consequence of the opening of 1a,, but in consequence of its slow action, keeps its armature attracted for a time sufiicient to allow the win III of B, to be energized before winding I is cut off at 108. Relay B1 remains energized during the series of impulses, while rela B at the repeater is short circuited and t ereby deenergized in consequence of the closing of contact 120 of relay V,

After the last lifting impulse, relay A at the repeater is continuously energized and in consequence of the opening of contact 100, relay V, is de-energized. The short circuit of relay B is removed at 120, and this relay is energized over the subscribers loop in series with relay A. At contact 114 earth is now permanently cut 05 from the lead a and relay A. at GW; is de-energized. Relay V when de-ener 'zed, disconnects battery at 118 from the 5 lead, so that the circuit of windin III of relay BI is o ened and the relay is e-energized, since re ay C is deenergized and contact 108 is already open. Relay C, remains energized, since the 0 lead is earthed by relay V at 104, or by relay V at 121.

When both relays A! and B release their armatures the circuit of the rotary magnet D is closed at 122 and 123 from earth, battery, interrupter U, all normal contact k, closed at the firzt lifting step, D, contact 124 of relay C,, 123, 122, earth. As soon as an idle line is found, relay B, which is connected to the outgoing lead 0 over contact 109 is energized. Contact 123 is o ned and magnet D de-energized. At the rst rotary step, contact 107 is opened and contact 107 closed, so that relay C, is maintained energized over contact 125 which is dependent on B,. When relay B, is energized, 125 is o ned; relay C, releases its armature and c oses thereby the contact 109'. The engaged potential, earth, is then applied at 126 to the outgoing 0 lead over relay MR, while relay B, connects itself over contact 125 and contact 107 to the incoming lead 0. Relay MR is energized at the same time with relay B, over lead 0. During the call, relays A and B as well as V, at the re ter, and relay1 B, at the group selector G 1 are energize If the subscriber V is the first to restore his receiver at the end of the conversation, relays A, B and V at the repeater are deenergized. At 104, earth is cut off from the lead 0, so that relay B, at the first group selector is deenergized. Relay B, at 126 opens the circuit of relay MR. Contact 127 is closed and the release circuit for the group selector GW; is closed from earth, 127, 128, M, k,, battery, earth. Since relay 0 is still energized relay S at the repeater U. is energized when contact 102 of relay V, is closed in a circuit from earth, battery, S, 102, 103, 129, earth. Relay S also at 130 short circuits relay C, which is thereby de-energized, and then opens at 103 the circuit of relay S; the

reselectors VW; and VW are thereby reeased in known manner, so that the normal condition of the circuit is again established.

If the wanted subscriber hangs u first, the relay MB of the group selector 8W is de-energized by the interruption of the current flowing over 0 at the selectors which succeed the group selector GW;. The circuit of the release magnet M is closed over contacts 145 and 127'. The lead 0 is opened at 107 when the group selector returns to its normal position, so that windings I and II of relay B, are also de-energized. The release of the repeater U. and the preselectors VWV, and VIV is effected when the receiver is restored at the calling subscribers station.

\Vhen the subscriber IV calls, the preselectors VW, and VW' 'are first set in known manner and when relay T at the preselector VIV'n is energized, it closes contact 131 and battery is applied to the lead 9. The further processes on the engagement of the repeater and the first group selector are at first the same as those above described. When relay C is energized, however, not only are the relays B, and C, at the first group selector ener d, but also a relay DC at the repeater in a circuit from earth, 113, 112, 9 lead, DC, 131, battery, earth. Re-

lay DC when energized, by opening the contact 132, prevents the a lead from being earthed, and by opening 119, revents the battery from being applied to t e I) lead, so that when the operator is connected up to the line, any knocking in her receiver is avoided. At the same time, rela DC connects at 133 the motor magnet of the service selector DW in a circuit from earth, 1 133, 134, D,, interrupter U,, battery, earth. The service selector seeks for an idle line to an operating position, and when this is found and relay T is thereby energized, remains stationary; relay T locks itself over 135 in a circuit inde endent of relay DC and connects at 136 an 137 the operators instrument set to the calling line. The operator then enquires for the wanted number and sets the sender in known manner, where- 2 by relay T, is energized.

Relay T at the contacts 138 and 139 cuts off the calling line from the leads a and b during the impulse transmission. Relay T also over its contact 140 connects earth which has been a plied by relay V at 104 to the c lead, to e lead g, so that when relay C at the group selector GW; is de-energized by is, being opened at the first liftin step relay DC still remains energized. Refay T also at 141 earths the lead d, so that relay T, is also independent of contact 142 of relay C. The series of impulses transmitted by the service selector set, as above described, the group selector GW At the end of the series of impulses the circuit of relay T is interrupted at the operators position or at the sender, so that the calling line is through connected to the wanted subscriber at 138 and 139. At 140 the circuit of relay DC is opened and at 141 or 143 also the circuit of relay T,; when relay T, is de-energized the operator is cut off from the connection. The release of the connection is efl'ected when the wanted subscriber restores his receiver as above described. If the subscriber W is the first to hang up his receiver, relays A, B and V, are deener 'zed as before at the repeater U,. Relay is energized and effects the chan es described above. so What claim and desire to protect by Letters atent is automatic switch, means for extending callaiinglinesofbothkindstosaidswltcha.

trunk line leading to an operator's position, discriminating means efiective only if the calling line is of a particular kind for connecting said switch with said second trunk line, and means for temporarily opening said first trunk line while the operator is controlling said switch.

3. In a telephone system, lines of two different kinds, a trunk line terminating in an automatic switch, a repeater included in said trunk line, means for extending calling lines of both kinds to said repeater, a trunk line leading to an operators position, and discriminating means in said repeater effective only if the calling line is of a particular kind for connecting said trunk lines to establish a three way connection involving the calling line, said switch, and the operators position.

4. In a telephone system, lines of two different kinds, a trunk line terminating in an automatic switch, means for extending calling lines of both kinds to said switch, a trunk line leading to an o rators position, discriminating means e ective only if the calling line is of a particular land for connecting said trunk hnes to establish a three way connection involving the calling line, said switch, and the operators osition, and means for cutting the calling line out of the connection while the operator is controlling said switch.

5. In a telephone 5 stem, lines of two different kinds, a tru line comprising two normally connected sections, the second section terminating in an automatic switch, a normally disconnected branch of said second section extending to an operators position, means for connecting any calling hne with the first section of said trunk line, and discriminating means effective only if the calling line is of a particular kind for connecting u? said branch.

6. n a telephone system, lines of two different kinds, a trunk line comprising two normally connected sections, the second section terminating in an automatic switch, a normally disconnected branch of said second section extending to an operators position, means for connecting any calling line with the first section of said trunk line, discriminating means efl'ective only if the calling line is of a particular kind for connecting up said branch, and means for separating said sections while the operator controls said switch.

7. In a telephone system, lines of two different kinds, a trunk line comprising two normally connected sections, the second section terminating in an automatic switch, a normal- 1y disconnected branch of said second section extending to an operators position, means for connecting any calling line with the first section of said trunk line, discriminating means effective only if the calling line is of a particular kind for connecting up said branch means for separating said sections while the operator controls said switch, and means whereby the two sections are again connected and the branch is disconnected 5 after the operation of said switch is completed.

8. In a telephone system, manual and automatic subscribers lines, automatic switches at the exchange for connecting said lines,

10 preselectors inserted in the system between the manual lines and said switches, other reselectors inserted between the automatic ms and said switches, said preselectors constituting means for connectin any calling line to an idle switch, a switching device for 1| further extending to an operators switchboard a calling line which has been connected to a switch, a conductor multipled in the banks of both manual and automatic line preselectors, means included only in the 20 manual preselectors for placing a potential on said conductor, and a relay controlled over said conductor for controlling said switching device.

EMIL TANKE. 

